Calculus - Understanding the derivative of a function at a point

In this video we'll cover what it means to be the derivative of a function at a point. This ties into the slope of a tangent line, as well as how a function is changing at a given point. Watch carefully how we use limits to build this definition of a derivative. Near the end I'll also show places where the derivative does not exsit. For more videos please visit http://www.mysecretmathtutor.com